Using Klebsiella pneumoniae to Model Acute Lung Inflammation in Mice

Lung infections caused by bacteria can induce a spectrum of immune responses, which is in part determined by the level of exposure and the degree of the host response. The host response involves pattern recognition receptors (PRRs) which sense pathogen and damage associated molecular patterns. Therefore, models of acute lung inflammation are necessary for further understanding the role of the innate immune system during bacterial infection in humans. Mice are a widely used model organism for studying important aspects of human lung pathogenesis, including acute and chronic inflammatory diseases. Klebsiella pneumoniae is a gram-negative bacterium that is commonly associated with respiratory infections, especially in a hospital setting. In this protocol, we describe a model of bacteria-mediated lung inflammation using K. pneumoniae. After a single intratracheal administration of K. pneumoniae, mice showed a strong level of Th1-mediated immune activation in the lungs. The model described here, while optimized for K. pneumonia, can be performed using other bacteria, fungi, and viruses as well.